Scientists have discovered liquid water reservoir on Mars – deep in the rocky outer crust of the planet, reports BBC.

New research on Mars shows that there is enough water beneath the Red Planet's surface to fill an entire ocean.

This discovery comes from a new analysis of data from NASA's Mars InSight probe, which landed on the Red Planet in 2018. The probe carried a seismograph that recorded the quadrennial vibrations – earthquakes from the depths of Mars.

By analyzing those earthquakes, exactly as the planet moves, they detected "seismic signals" of flowing water.

Although there is frozen water at the poles of Mars and evidence of steam in the atmosphere, this is the first time that flowing water has been found on the planet.

The findings were published in the journal "Proceedings of the National Academy of Sciences" (Proceedings of the National Academy of Sciences).

InSight's science mission ended in December 2022 after listening to the "pulse of Mars" for four years.

During that time, the probe observed more than 1.319 earthquakes.

By measuring the speed at which seismic waves travel, scientists have determined what material they are most likely traveling through.

- These are actually the same techniques we use to search for water on Earth or to search for oil and gas - explained Professor Michael Manga from the University of California at Berkeley, who participated in the research.

The analysis revealed water tanks at depths of approx 10 to 20 kilometers into the Martian crust.

"Understanding the water cycle on Mars is key to understanding the evolution of the climate, surface and interior," said research leader Dr. Vashan Wright from the San Diego Oceanographic Institute.

Professor Manga added that the water is "the most important molecule in shaping the evolution of the planet". This discovery, he said, answers the big question "Where did all the water from Mars go?".

Research on the surface of Mars shows that in ancient times on there were rivers and lakes on the planet.

But already three billion years, it's a desert.

Some of that water disappeared into space when Mars lost its atmosphere. But, said Professor Manga, here on Earth, "much of our water is underground, and there's no reason why that shouldn't be the case on Mars as well."

The InSight probe could only image directly from the crust beneath its feet, but researchers expect there to be similar reservoirs around the planet.

However, they point out, the location of that underground water not good news for billionaires planning to colonize Mars.

– It is trapped 10-20 kilometers deep in the crust. Drilling a hole 10 kilometers deep on Mars - even for Elon Musk - would be difficult - Manga told BBC News.

The discovery could also point to another goal in the search for evidence of life on Mars.

– Without running water you have no life. Therefore, if there are conditions for life on Mars, they could be deep underground - Professor Manga said.